The present invention relates to a technology effective when applied to a device structure technology or the like used in a power semiconductor device (or semiconductor integrated circuit device) such as an IE (Injection Enhancement)-type trench gate IGBT (Insulated Gate Bipolar Transistor) having a floating P type region.
There has been disclosed in Japanese Patent Laid-Open No. Hei 6 (1994)-13621 (Patent Document 1), a technology in which in a trench-type power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a P+ region is provided at a trench lower end to thereby relax the concentration of an electric field on the trench lower end.
There has been disclosed in Japanese Patent Laid-Open No. 2005-340626 (Patent Document 2) or U.S. Patent Publication No. 2009-39386 (Patent Document 3) corresponding to it, a technology in which in an IE-type IGBT, a floating P type region deeper than a trench in depth is provided at a floating cell portion, and another floating P type region is provided which surrounds a trench lower end lying between the floating cell portion and an active cell portion and is coupled to the floating P type region.
There has been disclosed in Japanese Patent Application Publication No. 2002-534811 (Patent Document 4) or U.S. Pat. No. 6,445,048 (Patent Document 5), a technology in which in an IE-type IGBT, a floating P type region deeper than a trench in depth is provided at a floating cell portion, and a termination structure including a structure similar to the floating cell portion is provided at an outer peripheral portion of the entire cell area.
There has been disclosed in Japanese Patent Laid-Open No. 2009-43782 (Patent Document 6), a technology in which a floating P type region having the same depth as a trench is provided at an IE-type IGBT.
There has been disclosed in Japanese Patent Laid-Open. No. 2000-307116 (Patent Document 7), a technology in which in an IE-type IGBT, a floating P body region deeper than a trench in depth is provided only at the central part of a floating cell portion in addition to a shallow floating P type region provided at the entire floating cell portion.
There has been disclosed in Japanese Patent Laid-Open No. 2010-50307 (Patent Document 8), a technology in which in a normal type IGBT other than an IE type, an N type hole barrier region is provided in a region including a trench's lower end.
[Patent Document 1] Japanese Patent Laid-Open No. Hei 6 (1994)-13621
[Patent Document 2] Japanese Patent Laid-Open No. 2005-340626
[Patent Document 3] U.S. Patent Publication No. 2009-39386
[Patent Document 4] Japanese Patent Application Publication No. 2002-534811
[Patent Document 5) U.S. Pat. No. 6,445,048
[Patent Document 6] Japanese Patent Laid-Open No. 2009-43782
[Patent Document 7] Japanese Patent Laid-Open No. 2000-307116
[Patent Document 8] Japanese Patent Laid-Open No. 2010-50307